Example #1
0
krb5_error_code
_kdc_as_rep(krb5_context context,
	    krb5_kdc_configuration *config,
	    KDC_REQ *req,
	    const krb5_data *req_buffer,
	    krb5_data *reply,
	    const char *from,
	    struct sockaddr *from_addr,
	    int datagram_reply)
{
    KDC_REQ_BODY *b = &req->req_body;
    AS_REP rep;
    KDCOptions f = b->kdc_options;
    hdb_entry_ex *client = NULL, *server = NULL;
    HDB *clientdb;
    krb5_enctype setype, sessionetype;
    krb5_data e_data;
    EncTicketPart et;
    EncKDCRepPart ek;
    krb5_principal client_princ = NULL, server_princ = NULL;
    char *client_name = NULL, *server_name = NULL;
    krb5_error_code ret = 0;
    const char *e_text = NULL;
    krb5_crypto crypto;
    Key *ckey, *skey;
    EncryptionKey *reply_key = NULL, session_key;
    int flags = HDB_F_FOR_AS_REQ;
#ifdef PKINIT
    pk_client_params *pkp = NULL;
#endif

    memset(&rep, 0, sizeof(rep));
    memset(&session_key, 0, sizeof(session_key));
    krb5_data_zero(&e_data);

    ALLOC(rep.padata);
    rep.padata->len = 0;
    rep.padata->val = NULL;

    if (f.canonicalize)
	flags |= HDB_F_CANON;

    if(b->sname == NULL){
	ret = KRB5KRB_ERR_GENERIC;
	e_text = "No server in request";
    } else{
	ret = _krb5_principalname2krb5_principal (context,
						  &server_princ,
						  *(b->sname),
						  b->realm);
	if (ret == 0)
	    ret = krb5_unparse_name(context, server_princ, &server_name);
    }
    if (ret) {
	kdc_log(context, config, 0,
		"AS-REQ malformed server name from %s", from);
	goto out;
    }
    if(b->cname == NULL){
	ret = KRB5KRB_ERR_GENERIC;
	e_text = "No client in request";
    } else {
	ret = _krb5_principalname2krb5_principal (context,
						  &client_princ,
						  *(b->cname),
						  b->realm);
	if (ret)
	    goto out;

	ret = krb5_unparse_name(context, client_princ, &client_name);
    }
    if (ret) {
	kdc_log(context, config, 0,
		"AS-REQ malformed client name from %s", from);
	goto out;
    }

    kdc_log(context, config, 0, "AS-REQ %s from %s for %s",
	    client_name, from, server_name);

    /*
     *
     */

    if (_kdc_is_anonymous(context, client_princ)) {
	if (!b->kdc_options.request_anonymous) {
	    kdc_log(context, config, 0, "Anonymous ticket w/o anonymous flag");
	    ret = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
	    goto out;
	}
    } else if (b->kdc_options.request_anonymous) {
	kdc_log(context, config, 0,
		"Request for a anonymous ticket with non "
		"anonymous client name: %s", client_name);
	ret = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
	goto out;
    }

    /*
     *
     */

    ret = _kdc_db_fetch(context, config, client_princ,
			HDB_F_GET_CLIENT | flags, NULL,
			&clientdb, &client);
    if(ret == HDB_ERR_NOT_FOUND_HERE) {
	kdc_log(context, config, 5, "client %s does not have secrets at this KDC, need to proxy", client_name);
	goto out;
    } else if(ret){
	const char *msg = krb5_get_error_message(context, ret);
	kdc_log(context, config, 0, "UNKNOWN -- %s: %s", client_name, msg);
	krb5_free_error_message(context, msg);
	ret = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
	goto out;
    }
    ret = _kdc_db_fetch(context, config, server_princ,
			HDB_F_GET_SERVER|HDB_F_GET_KRBTGT | flags,
			NULL, NULL, &server);
    if(ret == HDB_ERR_NOT_FOUND_HERE) {
	kdc_log(context, config, 5, "target %s does not have secrets at this KDC, need to proxy", server_name);
	goto out;
    } else if(ret){
	const char *msg = krb5_get_error_message(context, ret);
	kdc_log(context, config, 0, "UNKNOWN -- %s: %s", server_name, msg);
	krb5_free_error_message(context, msg);
	ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
	goto out;
    }

    memset(&et, 0, sizeof(et));
    memset(&ek, 0, sizeof(ek));

    /*
     * Select a session enctype from the list of the crypto system
     * supported enctypes that is supported by the client and is one of
     * the enctype of the enctype of the service (likely krbtgt).
     *
     * The latter is used as a hint of what enctypes all KDC support,
     * to make sure a newer version of KDC won't generate a session
     * enctype that an older version of a KDC in the same realm can't
     * decrypt.
     */
    ret = _kdc_find_etype(context, config->as_use_strongest_session_key, FALSE,
			  client, b->etype.val, b->etype.len, &sessionetype,
			  NULL);
    if (ret) {
	kdc_log(context, config, 0,
		"Client (%s) from %s has no common enctypes with KDC "
		"to use for the session key",
		client_name, from);
	goto out;
    }
    /*
     * But if the KDC admin is paranoid and doesn't want to have "not
     * the best" enctypes on the krbtgt, lets save the best pick from
     * the client list and hope that that will work for any other
     * KDCs.
     */

    /*
     * Pre-auth processing
     */

    if(req->padata){
	int i;
	const PA_DATA *pa;
	int found_pa = 0;

	log_patypes(context, config, req->padata);

#ifdef PKINIT
	kdc_log(context, config, 5,
		"Looking for PKINIT pa-data -- %s", client_name);

	e_text = "No PKINIT PA found";

	i = 0;
	pa = _kdc_find_padata(req, &i, KRB5_PADATA_PK_AS_REQ);
	if (pa == NULL) {
	    i = 0;
	    pa = _kdc_find_padata(req, &i, KRB5_PADATA_PK_AS_REQ_WIN);
	}
	if (pa) {
	    char *client_cert = NULL;

	    ret = _kdc_pk_rd_padata(context, config, req, pa, client, &pkp);
	    if (ret) {
		ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
		kdc_log(context, config, 5,
			"Failed to decode PKINIT PA-DATA -- %s",
			client_name);
		goto ts_enc;
	    }
	    if (ret == 0 && pkp == NULL)
		goto ts_enc;

	    ret = _kdc_pk_check_client(context,
				       config,
				       clientdb,
				       client,
				       pkp,
				       &client_cert);
	    if (ret) {
		e_text = "PKINIT certificate not allowed to "
		    "impersonate principal";
		_kdc_pk_free_client_param(context, pkp);

		kdc_log(context, config, 0, "%s", e_text);
		pkp = NULL;
		goto out;
	    }

	    found_pa = 1;
	    et.flags.pre_authent = 1;
	    kdc_log(context, config, 0,
		    "PKINIT pre-authentication succeeded -- %s using %s",
		    client_name, client_cert);
	    free(client_cert);
	    if (pkp)
		goto preauth_done;
	}
    ts_enc:
#endif

	if (client->entry.flags.locked_out) {
	    ret = KRB5KDC_ERR_CLIENT_REVOKED;
	    kdc_log(context, config, 0,
		    "Client (%s) is locked out", client_name);
	    goto out;
	}

	kdc_log(context, config, 5, "Looking for ENC-TS pa-data -- %s",
		client_name);

	i = 0;
	e_text = "No ENC-TS found";
	while((pa = _kdc_find_padata(req, &i, KRB5_PADATA_ENC_TIMESTAMP))){
	    krb5_data ts_data;
	    PA_ENC_TS_ENC p;
	    size_t len;
	    EncryptedData enc_data;
	    Key *pa_key;
	    char *str;

	    found_pa = 1;

	    if (b->kdc_options.request_anonymous) {
		ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
		kdc_log(context, config, 0, "ENC-TS doesn't support anon");
		goto out;
	    }

	    ret = decode_EncryptedData(pa->padata_value.data,
				       pa->padata_value.length,
				       &enc_data,
				       &len);
	    if (ret) {
		ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
		kdc_log(context, config, 5, "Failed to decode PA-DATA -- %s",
			client_name);
		goto out;
	    }

	    ret = hdb_enctype2key(context, &client->entry,
				  enc_data.etype, &pa_key);
	    if(ret){
		char *estr;
		e_text = "No key matches pa-data";
		ret = KRB5KDC_ERR_ETYPE_NOSUPP;
		if(krb5_enctype_to_string(context, enc_data.etype, &estr))
		    estr = NULL;
		if(estr == NULL)
		    kdc_log(context, config, 5,
			    "No client key matching pa-data (%d) -- %s",
			    enc_data.etype, client_name);
		else
		    kdc_log(context, config, 5,
			    "No client key matching pa-data (%s) -- %s",
			    estr, client_name);
		free(estr);
		free_EncryptedData(&enc_data);

		continue;
	    }

	try_next_key:
	    ret = krb5_crypto_init(context, &pa_key->key, 0, &crypto);
	    if (ret) {
		const char *msg = krb5_get_error_message(context, ret);
		kdc_log(context, config, 0, "krb5_crypto_init failed: %s", msg);
		krb5_free_error_message(context, msg);
		free_EncryptedData(&enc_data);
		continue;
	    }

	    ret = krb5_decrypt_EncryptedData (context,
					      crypto,
					      KRB5_KU_PA_ENC_TIMESTAMP,
					      &enc_data,
					      &ts_data);
	    krb5_crypto_destroy(context, crypto);
	    /*
	     * Since the user might have several keys with the same
	     * enctype but with diffrent salting, we need to try all
	     * the keys with the same enctype.
	     */
	    if(ret){
		krb5_error_code ret2;
		const char *msg = krb5_get_error_message(context, ret);

		ret2 = krb5_enctype_to_string(context,
					      pa_key->key.keytype, &str);
		if (ret2)
		    str = NULL;
		kdc_log(context, config, 5,
			"Failed to decrypt PA-DATA -- %s "
			"(enctype %s) error %s",
			client_name, str ? str : "unknown enctype", msg);
		krb5_free_error_message(context, msg);
		free(str);

		if(hdb_next_enctype2key(context, &client->entry,
					enc_data.etype, &pa_key) == 0)
		    goto try_next_key;
		e_text = "Failed to decrypt PA-DATA";

		free_EncryptedData(&enc_data);

		if (clientdb->hdb_auth_status)
		    (clientdb->hdb_auth_status)(context, clientdb, client, HDB_AUTH_WRONG_PASSWORD);

		ret = KRB5KDC_ERR_PREAUTH_FAILED;
		continue;
	    }
	    free_EncryptedData(&enc_data);
	    ret = decode_PA_ENC_TS_ENC(ts_data.data,
				       ts_data.length,
				       &p,
				       &len);
	    krb5_data_free(&ts_data);
	    if(ret){
		e_text = "Failed to decode PA-ENC-TS-ENC";
		ret = KRB5KDC_ERR_PREAUTH_FAILED;
		kdc_log(context, config,
			5, "Failed to decode PA-ENC-TS_ENC -- %s",
			client_name);
		continue;
	    }
	    free_PA_ENC_TS_ENC(&p);
	    if (abs(kdc_time - p.patimestamp) > context->max_skew) {
		char client_time[100];

		krb5_format_time(context, p.patimestamp,
				 client_time, sizeof(client_time), TRUE);

 		ret = KRB5KRB_AP_ERR_SKEW;
 		kdc_log(context, config, 0,
			"Too large time skew, "
			"client time %s is out by %u > %u seconds -- %s",
			client_time,
			(unsigned)abs(kdc_time - p.patimestamp),
			context->max_skew,
			client_name);

		/*
		 * The following is needed to make windows clients to
		 * retry using the timestamp in the error message, if
		 * there is a e_text, they become unhappy.
		 */
		e_text = NULL;
		goto out;
	    }
	    et.flags.pre_authent = 1;

	    set_salt_padata(rep.padata, pa_key->salt);

	    reply_key = &pa_key->key;

	    ret = krb5_enctype_to_string(context, pa_key->key.keytype, &str);
	    if (ret)
		str = NULL;

	    kdc_log(context, config, 2,
		    "ENC-TS Pre-authentication succeeded -- %s using %s",
		    client_name, str ? str : "unknown enctype");
	    free(str);
	    break;
	}
#ifdef PKINIT
    preauth_done:
#endif
	if(found_pa == 0 && config->require_preauth)
	    goto use_pa;
	/* We come here if we found a pa-enc-timestamp, but if there
           was some problem with it, other than too large skew */
	if(found_pa && et.flags.pre_authent == 0){
	    kdc_log(context, config, 0, "%s -- %s", e_text, client_name);
	    e_text = NULL;
	    goto out;
	}
    }else if (config->require_preauth
	      || b->kdc_options.request_anonymous /* hack to force anon */
	      || client->entry.flags.require_preauth
	      || server->entry.flags.require_preauth) {
	METHOD_DATA method_data;
	PA_DATA *pa;
	unsigned char *buf;
	size_t len;

    use_pa:
	method_data.len = 0;
	method_data.val = NULL;

	ret = realloc_method_data(&method_data);
	if (ret) {
	    free_METHOD_DATA(&method_data);
	    goto out;
	}
	pa = &method_data.val[method_data.len-1];
	pa->padata_type		= KRB5_PADATA_ENC_TIMESTAMP;
	pa->padata_value.length	= 0;
	pa->padata_value.data	= NULL;

#ifdef PKINIT
	ret = realloc_method_data(&method_data);
	if (ret) {
	    free_METHOD_DATA(&method_data);
	    goto out;
	}
	pa = &method_data.val[method_data.len-1];
	pa->padata_type		= KRB5_PADATA_PK_AS_REQ;
	pa->padata_value.length	= 0;
	pa->padata_value.data	= NULL;

	ret = realloc_method_data(&method_data);
	if (ret) {
	    free_METHOD_DATA(&method_data);
	    goto out;
	}
	pa = &method_data.val[method_data.len-1];
	pa->padata_type		= KRB5_PADATA_PK_AS_REQ_WIN;
	pa->padata_value.length	= 0;
	pa->padata_value.data	= NULL;
#endif

	/*
	 * If there is a client key, send ETYPE_INFO{,2}
	 */
	ret = _kdc_find_etype(context,
			      config->preauth_use_strongest_session_key, TRUE,
			      client, b->etype.val, b->etype.len, NULL, &ckey);
	if (ret == 0) {

	    /*
	     * RFC4120 requires:
	     * - If the client only knows about old enctypes, then send
	     *   both info replies (we send 'info' first in the list).
	     * - If the client is 'modern', because it knows about 'new'
	     *   enctype types, then only send the 'info2' reply.
	     *
	     * Before we send the full list of etype-info data, we pick
	     * the client key we would have used anyway below, just pick
	     * that instead.
	     */

	    if (older_enctype(ckey->key.keytype)) {
		ret = get_pa_etype_info(context, config,
					&method_data, ckey);
		if (ret) {
		    free_METHOD_DATA(&method_data);
		    goto out;
		}
	    }
	    ret = get_pa_etype_info2(context, config,
				     &method_data, ckey);
	    if (ret) {
		free_METHOD_DATA(&method_data);
		goto out;
	    }
	}

	ASN1_MALLOC_ENCODE(METHOD_DATA, buf, len, &method_data, &len, ret);
	free_METHOD_DATA(&method_data);

	e_data.data   = buf;
	e_data.length = len;
	e_text ="Need to use PA-ENC-TIMESTAMP/PA-PK-AS-REQ",

	ret = KRB5KDC_ERR_PREAUTH_REQUIRED;

	kdc_log(context, config, 0,
		"No preauth found, returning PREAUTH-REQUIRED -- %s",
		client_name);
	goto out;
    }

    /*
     * Verify flags after the user been required to prove its identity
     * with in a preauth mech.
     */

    ret = _kdc_check_access(context, config, client, client_name,
			    server, server_name,
			    req, &e_data);
    if(ret)
	goto out;

    if (clientdb->hdb_auth_status)
	(clientdb->hdb_auth_status)(context, clientdb, client,
				    HDB_AUTH_SUCCESS);

    /*
     * Selelct the best encryption type for the KDC with out regard to
     * the client since the client never needs to read that data.
     */

    ret = _kdc_get_preferred_key(context, config,
				 server, server_name,
				 &setype, &skey);
    if(ret)
	goto out;

    if(f.renew || f.validate || f.proxy || f.forwarded || f.enc_tkt_in_skey
       || (f.request_anonymous && !config->allow_anonymous)) {
	ret = KRB5KDC_ERR_BADOPTION;
	e_text = "Bad KDC options";
	kdc_log(context, config, 0, "Bad KDC options -- %s", client_name);
	goto out;
    }

    rep.pvno = 5;
    rep.msg_type = krb_as_rep;

    ret = copy_Realm(&client->entry.principal->realm, &rep.crealm);
    if (ret)
	goto out;
    ret = _krb5_principal2principalname(&rep.cname, client->entry.principal);
    if (ret)
	goto out;

    rep.ticket.tkt_vno = 5;
    copy_Realm(&server->entry.principal->realm, &rep.ticket.realm);
    _krb5_principal2principalname(&rep.ticket.sname,
				  server->entry.principal);
    /* java 1.6 expects the name to be the same type, lets allow that
     * uncomplicated name-types. */
#define CNT(sp,t) (((sp)->sname->name_type) == KRB5_NT_##t)
    if (CNT(b, UNKNOWN) || CNT(b, PRINCIPAL) || CNT(b, SRV_INST) || CNT(b, SRV_HST) || CNT(b, SRV_XHST))
	rep.ticket.sname.name_type = b->sname->name_type;
#undef CNT

    et.flags.initial = 1;
    if(client->entry.flags.forwardable && server->entry.flags.forwardable)
	et.flags.forwardable = f.forwardable;
    else if (f.forwardable) {
	e_text = "Ticket may not be forwardable";
	ret = KRB5KDC_ERR_POLICY;
	kdc_log(context, config, 0,
		"Ticket may not be forwardable -- %s", client_name);
	goto out;
    }
    if(client->entry.flags.proxiable && server->entry.flags.proxiable)
	et.flags.proxiable = f.proxiable;
    else if (f.proxiable) {
	e_text = "Ticket may not be proxiable";
	ret = KRB5KDC_ERR_POLICY;
	kdc_log(context, config, 0,
		"Ticket may not be proxiable -- %s", client_name);
	goto out;
    }
    if(client->entry.flags.postdate && server->entry.flags.postdate)
	et.flags.may_postdate = f.allow_postdate;
    else if (f.allow_postdate){
	e_text = "Ticket may not be postdate";
	ret = KRB5KDC_ERR_POLICY;
	kdc_log(context, config, 0,
		"Ticket may not be postdatable -- %s", client_name);
	goto out;
    }

    /* check for valid set of addresses */
    if(!_kdc_check_addresses(context, config, b->addresses, from_addr)) {
	e_text = "Bad address list in requested";
	ret = KRB5KRB_AP_ERR_BADADDR;
	kdc_log(context, config, 0,
		"Bad address list requested -- %s", client_name);
	goto out;
    }

    ret = copy_PrincipalName(&rep.cname, &et.cname);
    if (ret)
	goto out;
    ret = copy_Realm(&rep.crealm, &et.crealm);
    if (ret)
	goto out;

    {
	time_t start;
	time_t t;

	start = et.authtime = kdc_time;

	if(f.postdated && req->req_body.from){
	    ALLOC(et.starttime);
	    start = *et.starttime = *req->req_body.from;
	    et.flags.invalid = 1;
	    et.flags.postdated = 1; /* XXX ??? */
	}
	_kdc_fix_time(&b->till);
	t = *b->till;

	/* be careful not overflowing */

	if(client->entry.max_life)
	    t = start + min(t - start, *client->entry.max_life);
	if(server->entry.max_life)
	    t = start + min(t - start, *server->entry.max_life);
#if 0
	t = min(t, start + realm->max_life);
#endif
	et.endtime = t;
	if(f.renewable_ok && et.endtime < *b->till){
	    f.renewable = 1;
	    if(b->rtime == NULL){
		ALLOC(b->rtime);
		*b->rtime = 0;
	    }
	    if(*b->rtime < *b->till)
		*b->rtime = *b->till;
	}
	if(f.renewable && b->rtime){
	    t = *b->rtime;
	    if(t == 0)
		t = MAX_TIME;
	    if(client->entry.max_renew)
		t = start + min(t - start, *client->entry.max_renew);
	    if(server->entry.max_renew)
		t = start + min(t - start, *server->entry.max_renew);
#if 0
	    t = min(t, start + realm->max_renew);
#endif
	    ALLOC(et.renew_till);
	    *et.renew_till = t;
	    et.flags.renewable = 1;
	}
    }

    if (f.request_anonymous)
	et.flags.anonymous = 1;

    if(b->addresses){
	ALLOC(et.caddr);
	copy_HostAddresses(b->addresses, et.caddr);
    }

    et.transited.tr_type = DOMAIN_X500_COMPRESS;
    krb5_data_zero(&et.transited.contents);

    /* The MIT ASN.1 library (obviously) doesn't tell lengths encoded
     * as 0 and as 0x80 (meaning indefinite length) apart, and is thus
     * incapable of correctly decoding SEQUENCE OF's of zero length.
     *
     * To fix this, always send at least one no-op last_req
     *
     * If there's a pw_end or valid_end we will use that,
     * otherwise just a dummy lr.
     */
    ek.last_req.val = malloc(2 * sizeof(*ek.last_req.val));
    if (ek.last_req.val == NULL) {
	ret = ENOMEM;
	goto out;
    }
    ek.last_req.len = 0;
    if (client->entry.pw_end
	&& (config->kdc_warn_pwexpire == 0
	    || kdc_time + config->kdc_warn_pwexpire >= *client->entry.pw_end)) {
	ek.last_req.val[ek.last_req.len].lr_type  = LR_PW_EXPTIME;
	ek.last_req.val[ek.last_req.len].lr_value = *client->entry.pw_end;
	++ek.last_req.len;
    }
    if (client->entry.valid_end) {
	ek.last_req.val[ek.last_req.len].lr_type  = LR_ACCT_EXPTIME;
	ek.last_req.val[ek.last_req.len].lr_value = *client->entry.valid_end;
	++ek.last_req.len;
    }
    if (ek.last_req.len == 0) {
	ek.last_req.val[ek.last_req.len].lr_type  = LR_NONE;
	ek.last_req.val[ek.last_req.len].lr_value = 0;
	++ek.last_req.len;
    }
    ek.nonce = b->nonce;
    if (client->entry.valid_end || client->entry.pw_end) {
	ALLOC(ek.key_expiration);
	if (client->entry.valid_end) {
	    if (client->entry.pw_end)
		*ek.key_expiration = min(*client->entry.valid_end,
					 *client->entry.pw_end);
	    else
		*ek.key_expiration = *client->entry.valid_end;
	} else
	    *ek.key_expiration = *client->entry.pw_end;
    } else
	ek.key_expiration = NULL;
    ek.flags = et.flags;
    ek.authtime = et.authtime;
    if (et.starttime) {
	ALLOC(ek.starttime);
	*ek.starttime = *et.starttime;
    }
    ek.endtime = et.endtime;
    if (et.renew_till) {
	ALLOC(ek.renew_till);
	*ek.renew_till = *et.renew_till;
    }
    copy_Realm(&rep.ticket.realm, &ek.srealm);
    copy_PrincipalName(&rep.ticket.sname, &ek.sname);
    if(et.caddr){
	ALLOC(ek.caddr);
	copy_HostAddresses(et.caddr, ek.caddr);
    }

#if PKINIT
    if (pkp) {
        e_text = "Failed to build PK-INIT reply";
	ret = _kdc_pk_mk_pa_reply(context, config, pkp, client,
				  sessionetype, req, req_buffer,
				  &reply_key, &et.key, rep.padata);
	if (ret)
	    goto out;
	ret = _kdc_add_inital_verified_cas(context,
					   config,
					   pkp,
					   &et);
	if (ret)
	    goto out;

    } else
#endif
    {
	ret = krb5_generate_random_keyblock(context, sessionetype, &et.key);
	if (ret)
	    goto out;
    }

    if (reply_key == NULL) {
	e_text = "Client have no reply key";
	ret = KRB5KDC_ERR_CLIENT_NOTYET;
	goto out;
    }

    ret = copy_EncryptionKey(&et.key, &ek.key);
    if (ret)
	goto out;

    if (rep.padata->len == 0) {
	free(rep.padata);
	rep.padata = NULL;
    }

    /* Add the PAC */
    if (send_pac_p(context, req)) {
	krb5_pac p = NULL;
	krb5_data data;

	ret = _kdc_pac_generate(context, client, &p);
	if (ret) {
	    kdc_log(context, config, 0, "PAC generation failed for -- %s",
		    client_name);
	    goto out;
	}
	if (p != NULL) {
	    ret = _krb5_pac_sign(context, p, et.authtime,
				 client->entry.principal,
				 &skey->key, /* Server key */
				 &skey->key, /* FIXME: should be krbtgt key */
				 &data);
	    krb5_pac_free(context, p);
	    if (ret) {
		kdc_log(context, config, 0, "PAC signing failed for -- %s",
			client_name);
		goto out;
	    }

	    ret = _kdc_tkt_add_if_relevant_ad(context, &et,
					      KRB5_AUTHDATA_WIN2K_PAC,
					      &data);
	    krb5_data_free(&data);
	    if (ret)
		goto out;
	}
    }

    _kdc_log_timestamp(context, config, "AS-REQ", et.authtime, et.starttime,
		       et.endtime, et.renew_till);

    /* do this as the last thing since this signs the EncTicketPart */
    ret = _kdc_add_KRB5SignedPath(context,
				  config,
				  server,
				  setype,
				  client->entry.principal,
				  NULL,
				  NULL,
				  &et);
    if (ret)
	goto out;

    log_as_req(context, config, reply_key->keytype, setype, b);

    ret = _kdc_encode_reply(context, config,
			    &rep, &et, &ek, setype, server->entry.kvno,
			    &skey->key, client->entry.kvno,
			    reply_key, 0, &e_text, reply);
    free_EncTicketPart(&et);
    free_EncKDCRepPart(&ek);
    if (ret)
	goto out;

    /* */
    if (datagram_reply && reply->length > config->max_datagram_reply_length) {
	krb5_data_free(reply);
	ret = KRB5KRB_ERR_RESPONSE_TOO_BIG;
	e_text = "Reply packet too large";
    }

out:
    free_AS_REP(&rep);
    if(ret != 0 && ret != HDB_ERR_NOT_FOUND_HERE){
	krb5_mk_error(context,
		      ret,
		      e_text,
		      (e_data.data ? &e_data : NULL),
		      client_princ,
		      server_princ,
		      NULL,
		      NULL,
		      reply);
	ret = 0;
    }
#ifdef PKINIT
    if (pkp)
	_kdc_pk_free_client_param(context, pkp);
#endif
    if (e_data.data)
        free(e_data.data);
    if (client_princ)
	krb5_free_principal(context, client_princ);
    free(client_name);
    if (server_princ)
	krb5_free_principal(context, server_princ);
    free(server_name);
    if(client)
	_kdc_free_ent(context, client);
    if(server)
	_kdc_free_ent(context, server);
    return ret;
}
Example #2
0
static krb5_error_code
tgs_make_reply(krb5_context context, 
	       krb5_kdc_configuration *config,
	       KDC_REQ_BODY *b, 
	       krb5_const_principal tgt_name,
	       const EncTicketPart *tgt, 
	       const EncryptionKey *serverkey,
	       const krb5_keyblock *sessionkey,
	       krb5_kvno kvno,
	       AuthorizationData *auth_data,
	       hdb_entry_ex *server, 
	       const char *server_name, 
	       hdb_entry_ex *client, 
	       krb5_principal client_principal, 
	       hdb_entry_ex *krbtgt,
	       krb5_enctype krbtgt_etype,
	       KRB5SignedPathPrincipals *spp,
	       const krb5_data *rspac,
	       const char **e_text,
	       krb5_data *reply)
{
    KDC_REP rep;
    EncKDCRepPart ek;
    EncTicketPart et;
    KDCOptions f = b->kdc_options;
    krb5_error_code ret;
    
    memset(&rep, 0, sizeof(rep));
    memset(&et, 0, sizeof(et));
    memset(&ek, 0, sizeof(ek));
    
    rep.pvno = 5;
    rep.msg_type = krb_tgs_rep;

    et.authtime = tgt->authtime;
    _kdc_fix_time(&b->till);
    et.endtime = min(tgt->endtime, *b->till);
    ALLOC(et.starttime);
    *et.starttime = kdc_time;
    
    ret = check_tgs_flags(context, config, b, tgt, &et);
    if(ret)
	goto out;

    /* We should check the transited encoding if:
       1) the request doesn't ask not to be checked
       2) globally enforcing a check
       3) principal requires checking
       4) we allow non-check per-principal, but principal isn't marked as allowing this
       5) we don't globally allow this
    */

#define GLOBAL_FORCE_TRANSITED_CHECK		\
    (config->trpolicy == TRPOLICY_ALWAYS_CHECK)
#define GLOBAL_ALLOW_PER_PRINCIPAL			\
    (config->trpolicy == TRPOLICY_ALLOW_PER_PRINCIPAL)
#define GLOBAL_ALLOW_DISABLE_TRANSITED_CHECK			\
    (config->trpolicy == TRPOLICY_ALWAYS_HONOUR_REQUEST)

/* these will consult the database in future release */
#define PRINCIPAL_FORCE_TRANSITED_CHECK(P)		0
#define PRINCIPAL_ALLOW_DISABLE_TRANSITED_CHECK(P)	0

    ret = fix_transited_encoding(context, config, 
				 !f.disable_transited_check ||
				 GLOBAL_FORCE_TRANSITED_CHECK ||
				 PRINCIPAL_FORCE_TRANSITED_CHECK(server) ||
				 !((GLOBAL_ALLOW_PER_PRINCIPAL && 
				    PRINCIPAL_ALLOW_DISABLE_TRANSITED_CHECK(server)) ||
				   GLOBAL_ALLOW_DISABLE_TRANSITED_CHECK),
				 &tgt->transited, &et,
				 *krb5_princ_realm(context, client_principal),
				 *krb5_princ_realm(context, server->entry.principal),
				 *krb5_princ_realm(context, krbtgt->entry.principal));
    if(ret)
	goto out;

    copy_Realm(krb5_princ_realm(context, server->entry.principal), 
	       &rep.ticket.realm);
    _krb5_principal2principalname(&rep.ticket.sname, server->entry.principal);
    copy_Realm(&tgt_name->realm, &rep.crealm);
/*
    if (f.request_anonymous)
	_kdc_make_anonymous_principalname (&rep.cname);
    else */

    copy_PrincipalName(&tgt_name->name, &rep.cname);
    rep.ticket.tkt_vno = 5;

    ek.caddr = et.caddr;
    if(et.caddr == NULL)
	et.caddr = tgt->caddr;

    {
	time_t life;
	life = et.endtime - *et.starttime;
	if(client && client->entry.max_life)
	    life = min(life, *client->entry.max_life);
	if(server->entry.max_life)
	    life = min(life, *server->entry.max_life);
	et.endtime = *et.starttime + life;
    }
    if(f.renewable_ok && tgt->flags.renewable && 
       et.renew_till == NULL && et.endtime < *b->till){
	et.flags.renewable = 1;
	ALLOC(et.renew_till);
	*et.renew_till = *b->till;
    }
    if(et.renew_till){
	time_t renew;
	renew = *et.renew_till - et.authtime;
	if(client && client->entry.max_renew)
	    renew = min(renew, *client->entry.max_renew);
	if(server->entry.max_renew)
	    renew = min(renew, *server->entry.max_renew);
	*et.renew_till = et.authtime + renew;
    }
	    
    if(et.renew_till){
	*et.renew_till = min(*et.renew_till, *tgt->renew_till);
	*et.starttime = min(*et.starttime, *et.renew_till);
	et.endtime = min(et.endtime, *et.renew_till);
    }
    
    *et.starttime = min(*et.starttime, et.endtime);

    if(*et.starttime == et.endtime){
	ret = KRB5KDC_ERR_NEVER_VALID;
	goto out;
    }
    if(et.renew_till && et.endtime == *et.renew_till){
	free(et.renew_till);
	et.renew_till = NULL;
	et.flags.renewable = 0;
    }
    
    et.flags.pre_authent = tgt->flags.pre_authent;
    et.flags.hw_authent  = tgt->flags.hw_authent;
    et.flags.anonymous   = tgt->flags.anonymous;
    et.flags.ok_as_delegate = server->entry.flags.ok_as_delegate;
	    
    if (auth_data) {
	/* XXX Check enc-authorization-data */
	et.authorization_data = calloc(1, sizeof(*et.authorization_data));
	if (et.authorization_data == NULL) {
	    ret = ENOMEM;
	    goto out;
	}
	ret = copy_AuthorizationData(auth_data, et.authorization_data);
	if (ret)
	    goto out;

	/* Filter out type KRB5SignedPath */
	ret = find_KRB5SignedPath(context, et.authorization_data, NULL);
	if (ret == 0) {
	    if (et.authorization_data->len == 1) {
		free_AuthorizationData(et.authorization_data);
		free(et.authorization_data);
		et.authorization_data = NULL;
	    } else {
		AuthorizationData *ad = et.authorization_data;
		free_AuthorizationDataElement(&ad->val[ad->len - 1]);
		ad->len--;
	    }
	}
    }

    if(rspac->length) {
	/*
	 * No not need to filter out the any PAC from the
	 * auth_data since its signed by the KDC.
	 */
	ret = _kdc_tkt_add_if_relevant_ad(context, &et,
					  KRB5_AUTHDATA_WIN2K_PAC,
					  rspac);
	if (ret)
	    goto out;
    }

    ret = krb5_copy_keyblock_contents(context, sessionkey, &et.key);
    if (ret)
	goto out;
    et.crealm = tgt->crealm;
    et.cname = tgt_name->name;
	    
    ek.key = et.key;
    /* MIT must have at least one last_req */
    ek.last_req.len = 1;
    ek.last_req.val = calloc(1, sizeof(*ek.last_req.val));
    if (ek.last_req.val == NULL) {
	ret = ENOMEM;
	goto out;
    }
    ek.nonce = b->nonce;
    ek.flags = et.flags;
    ek.authtime = et.authtime;
    ek.starttime = et.starttime;
    ek.endtime = et.endtime;
    ek.renew_till = et.renew_till;
    ek.srealm = rep.ticket.realm;
    ek.sname = rep.ticket.sname;
    
    _kdc_log_timestamp(context, config, "TGS-REQ", et.authtime, et.starttime, 
		       et.endtime, et.renew_till);

    /* Don't sign cross realm tickets, they can't be checked anyway */
    {
	char *r = get_krbtgt_realm(&ek.sname);

	if (r == NULL || strcmp(r, ek.srealm) == 0) {
	    ret = _kdc_add_KRB5SignedPath(context,
					  config,
					  krbtgt,
					  krbtgt_etype,
					  NULL,
					  spp,
					  &et);
	    if (ret)
		goto out;
	}
    }

    /* It is somewhat unclear where the etype in the following
       encryption should come from. What we have is a session
       key in the passed tgt, and a list of preferred etypes
       *for the new ticket*. Should we pick the best possible
       etype, given the keytype in the tgt, or should we look
       at the etype list here as well?  What if the tgt
       session key is DES3 and we want a ticket with a (say)
       CAST session key. Should the DES3 etype be added to the
       etype list, even if we don't want a session key with
       DES3? */
    ret = _kdc_encode_reply(context, config, 
			    &rep, &et, &ek, et.key.keytype,
			    kvno, 
			    serverkey, 0, &tgt->key, e_text, reply);
out:
    free_TGS_REP(&rep);
    free_TransitedEncoding(&et.transited);
    if(et.starttime)
	free(et.starttime);
    if(et.renew_till)
	free(et.renew_till);
    if(et.authorization_data) {
	free_AuthorizationData(et.authorization_data);
	free(et.authorization_data);
    }
    free_LastReq(&ek.last_req);
    memset(et.key.keyvalue.data, 0, et.key.keyvalue.length);
    free_EncryptionKey(&et.key);
    return ret;
}
Example #3
0
krb5_error_code
_kdc_as_rep(krb5_context context, 
	    krb5_kdc_configuration *config,
	    KDC_REQ *req, 
	    const krb5_data *req_buffer, 
	    krb5_data *reply,
	    const char *from,
	    struct sockaddr *from_addr,
	    int datagram_reply)
{
    KDC_REQ_BODY *b = &req->req_body;
    AS_REP rep;
    KDCOptions f = b->kdc_options;
    hdb_entry_ex *client = NULL, *server = NULL;
    krb5_enctype cetype, setype, sessionetype;
    krb5_data e_data;
    EncTicketPart et;
    EncKDCRepPart ek;
    krb5_principal client_princ = NULL, server_princ = NULL;
    char *client_name = NULL, *server_name = NULL;
    krb5_error_code ret = 0;
    const char *e_text = NULL;
    krb5_crypto crypto;
    Key *ckey, *skey;
    EncryptionKey *reply_key;
    int flags = 0;
#ifdef PKINIT
    pk_client_params *pkp = NULL;
#endif

    memset(&rep, 0, sizeof(rep));
    krb5_data_zero(&e_data);

    if (f.canonicalize)
	flags |= HDB_F_CANON;

    if(b->sname == NULL){
	ret = KRB5KRB_ERR_GENERIC;
	e_text = "No server in request";
    } else{
	ret = _krb5_principalname2krb5_principal (context,
						  &server_princ,
						  *(b->sname),
						  b->realm);
	if (ret == 0)
	    ret = krb5_unparse_name(context, server_princ, &server_name);
    }
    if (ret) {
	kdc_log(context, config, 0, 
		"AS-REQ malformed server name from %s", from);
	goto out;
    }
    
    if(b->cname == NULL){
	ret = KRB5KRB_ERR_GENERIC;
	e_text = "No client in request";
    } else {

	if (b->cname->name_type == KRB5_NT_ENTERPRISE_PRINCIPAL) {
	    if (b->cname->name_string.len != 1) {
		kdc_log(context, config, 0,
			"AS-REQ malformed canon request from %s, "
			"enterprise name with %d name components", 
			from, b->cname->name_string.len);
		ret = KRB5_PARSE_MALFORMED;
		goto out;
	    }
	    ret = krb5_parse_name(context, b->cname->name_string.val[0],
				  &client_princ);
	    if (ret)
		goto out;
	} else {
	    ret = _krb5_principalname2krb5_principal (context,
						      &client_princ,
						      *(b->cname),
						      b->realm);
	    if (ret)
		goto out;
	}
	ret = krb5_unparse_name(context, client_princ, &client_name);
    }
    if (ret) {
	kdc_log(context, config, 0,
		"AS-REQ malformed client name from %s", from);
	goto out;
    }

    kdc_log(context, config, 0, "AS-REQ %s from %s for %s", 
	    client_name, from, server_name);

    ret = _kdc_db_fetch(context, config, client_princ, 
			HDB_F_GET_CLIENT | flags, NULL, &client);
    if(ret){
	kdc_log(context, config, 0, "UNKNOWN -- %s: %s", client_name,
		krb5_get_err_text(context, ret));
	ret = KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN;
	goto out;
    }

    ret = _kdc_db_fetch(context, config, server_princ,
			HDB_F_GET_SERVER|HDB_F_GET_KRBTGT,
			NULL, &server);
    if(ret){
	kdc_log(context, config, 0, "UNKNOWN -- %s: %s", server_name,
		krb5_get_err_text(context, ret));
	ret = KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN;
	goto out;
    }

    ret = _kdc_windc_client_access(context, client, req);
    if(ret)
	goto out;

    ret = _kdc_check_flags(context, config, 
			   client, client_name,
			   server, server_name,
			   TRUE);
    if(ret)
	goto out;

    memset(&et, 0, sizeof(et));
    memset(&ek, 0, sizeof(ek));

    if(req->padata){
	int i;
	const PA_DATA *pa;
	int found_pa = 0;

	log_patypes(context, config, req->padata);

#ifdef PKINIT
	kdc_log(context, config, 5, 
		"Looking for PKINIT pa-data -- %s", client_name);

	e_text = "No PKINIT PA found";

	i = 0;
	if ((pa = _kdc_find_padata(req, &i, KRB5_PADATA_PK_AS_REQ)))
	    ;
	if (pa == NULL) {
	    i = 0;
	    if((pa = _kdc_find_padata(req, &i, KRB5_PADATA_PK_AS_REQ_WIN)))
		;
	}
	if (pa) {
	    char *client_cert = NULL;

	    ret = _kdc_pk_rd_padata(context, config, req, pa, &pkp);
	    if (ret) {
		ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
		kdc_log(context, config, 5, 
			"Failed to decode PKINIT PA-DATA -- %s", 
			client_name);
		goto ts_enc;
	    }
	    if (ret == 0 && pkp == NULL)
		goto ts_enc;

	    ret = _kdc_pk_check_client(context,
				       config,
				       client,
				       pkp,
				       &client_cert);
	    if (ret) {
		e_text = "PKINIT certificate not allowed to "
		    "impersonate principal";
		_kdc_pk_free_client_param(context, pkp);

		kdc_log(context, config, 0, "%s", e_text);
		pkp = NULL;
		goto out;
	    }
	    found_pa = 1;
	    et.flags.pre_authent = 1;
	    kdc_log(context, config, 0,
		    "PKINIT pre-authentication succeeded -- %s using %s", 
		    client_name, client_cert);
	    free(client_cert);
	    if (pkp)
		goto preauth_done;
	}
    ts_enc:
#endif
	kdc_log(context, config, 5, "Looking for ENC-TS pa-data -- %s", 
		client_name);

	i = 0;
	e_text = "No ENC-TS found";
	while((pa = _kdc_find_padata(req, &i, KRB5_PADATA_ENC_TIMESTAMP))){
	    krb5_data ts_data;
	    PA_ENC_TS_ENC p;
	    size_t len;
	    EncryptedData enc_data;
	    Key *pa_key;
	    char *str;
	    
	    found_pa = 1;
	    
	    ret = decode_EncryptedData(pa->padata_value.data,
				       pa->padata_value.length,
				       &enc_data,
				       &len);
	    if (ret) {
		ret = KRB5KRB_AP_ERR_BAD_INTEGRITY;
		kdc_log(context, config, 5, "Failed to decode PA-DATA -- %s", 
			client_name);
		goto out;
	    }
	    
	    ret = hdb_enctype2key(context, &client->entry, 
				  enc_data.etype, &pa_key);
	    if(ret){
		char *estr;
		e_text = "No key matches pa-data";
		ret = KRB5KDC_ERR_ETYPE_NOSUPP;
		if(krb5_enctype_to_string(context, enc_data.etype, &estr))
		    estr = NULL;
		if(estr == NULL)
		    kdc_log(context, config, 5, 
			    "No client key matching pa-data (%d) -- %s", 
			    enc_data.etype, client_name);
		else
		    kdc_log(context, config, 5,
			    "No client key matching pa-data (%s) -- %s", 
			    estr, client_name);
		free(estr);
		    
		free_EncryptedData(&enc_data);
		continue;
	    }

	try_next_key:
	    ret = krb5_crypto_init(context, &pa_key->key, 0, &crypto);
	    if (ret) {
		kdc_log(context, config, 0, "krb5_crypto_init failed: %s",
			krb5_get_err_text(context, ret));
		free_EncryptedData(&enc_data);
		continue;
	    }

	    ret = krb5_decrypt_EncryptedData (context,
					      crypto,
					      KRB5_KU_PA_ENC_TIMESTAMP,
					      &enc_data,
					      &ts_data);
	    krb5_crypto_destroy(context, crypto);
	    if(ret){
		krb5_error_code ret2;
		ret2 = krb5_enctype_to_string(context, 
					      pa_key->key.keytype, &str);
		if (ret2)
		    str = NULL;
		kdc_log(context, config, 5, 
			"Failed to decrypt PA-DATA -- %s "
			"(enctype %s) error %s",
			client_name,
			str ? str : "unknown enctype", 
			krb5_get_err_text(context, ret));
		free(str);

		if(hdb_next_enctype2key(context, &client->entry, 
					enc_data.etype, &pa_key) == 0)
		    goto try_next_key;
		e_text = "Failed to decrypt PA-DATA";

		free_EncryptedData(&enc_data);
		ret = KRB5KDC_ERR_PREAUTH_FAILED;
		continue;
	    }
	    free_EncryptedData(&enc_data);
	    ret = decode_PA_ENC_TS_ENC(ts_data.data,
				       ts_data.length,
				       &p,
				       &len);
	    krb5_data_free(&ts_data);
	    if(ret){
		e_text = "Failed to decode PA-ENC-TS-ENC";
		ret = KRB5KDC_ERR_PREAUTH_FAILED;
		kdc_log(context, config, 
			5, "Failed to decode PA-ENC-TS_ENC -- %s",
			client_name);
		continue;
	    }
	    free_PA_ENC_TS_ENC(&p);
	    if (abs(kdc_time - p.patimestamp) > context->max_skew) {
		char client_time[100];
		
		krb5_format_time(context, p.patimestamp, 
				 client_time, sizeof(client_time), TRUE); 

 		ret = KRB5KRB_AP_ERR_SKEW;
 		kdc_log(context, config, 0,
			"Too large time skew, "
			"client time %s is out by %u > %u seconds -- %s", 
			client_time, 
			(unsigned)abs(kdc_time - p.patimestamp), 
			context->max_skew,
			client_name);
#if 0
		/* This code is from samba, needs testing */
		/* 
		 * the following is needed to make windows clients
		 * to retry using the timestamp in the error message
		 *
		 * this is maybe a bug in windows to not trying when e_text
		 * is present...
		 */
		e_text = NULL;
#else
		e_text = "Too large time skew";
#endif
		goto out;
	    }
	    et.flags.pre_authent = 1;

	    ret = krb5_enctype_to_string(context,pa_key->key.keytype, &str);
	    if (ret)
		str = NULL;

	    kdc_log(context, config, 2,
		    "ENC-TS Pre-authentication succeeded -- %s using %s", 
		    client_name, str ? str : "unknown enctype");
	    free(str);
	    break;
	}
#ifdef PKINIT
    preauth_done:
#endif
	if(found_pa == 0 && config->require_preauth)
	    goto use_pa;
	/* We come here if we found a pa-enc-timestamp, but if there
           was some problem with it, other than too large skew */
	if(found_pa && et.flags.pre_authent == 0){
	    kdc_log(context, config, 0, "%s -- %s", e_text, client_name);
	    e_text = NULL;
	    goto out;
	}
    }else if (config->require_preauth
	      || client->entry.flags.require_preauth
	      || server->entry.flags.require_preauth) {
	METHOD_DATA method_data;
	PA_DATA *pa;
	unsigned char *buf;
	size_t len;

    use_pa: 
	method_data.len = 0;
	method_data.val = NULL;

	ret = realloc_method_data(&method_data);
	pa = &method_data.val[method_data.len-1];
	pa->padata_type		= KRB5_PADATA_ENC_TIMESTAMP;
	pa->padata_value.length	= 0;
	pa->padata_value.data	= NULL;

#ifdef PKINIT
	ret = realloc_method_data(&method_data);
	pa = &method_data.val[method_data.len-1];
	pa->padata_type		= KRB5_PADATA_PK_AS_REQ;
	pa->padata_value.length	= 0;
	pa->padata_value.data	= NULL;

	ret = realloc_method_data(&method_data);
	pa = &method_data.val[method_data.len-1];
	pa->padata_type		= KRB5_PADATA_PK_AS_REQ_WIN;
	pa->padata_value.length	= 0;
	pa->padata_value.data	= NULL;
#endif

	/* 
	 * RFC4120 requires: 
	 * - If the client only knows about old enctypes, then send
	 *   both info replies (we send 'info' first in the list).
	 * - If the client is 'modern', because it knows about 'new'
	 *   enctype types, then only send the 'info2' reply.
	 */

	/* XXX check ret */
	if (only_older_enctype_p(req))
	    ret = get_pa_etype_info(context, config,
				    &method_data, &client->entry, 
				    b->etype.val, b->etype.len); 
	/* XXX check ret */
	ret = get_pa_etype_info2(context, config, &method_data, 
				 &client->entry, b->etype.val, b->etype.len);

	
	ASN1_MALLOC_ENCODE(METHOD_DATA, buf, len, &method_data, &len, ret);
	free_METHOD_DATA(&method_data);

	e_data.data   = buf;
	e_data.length = len;
	e_text ="Need to use PA-ENC-TIMESTAMP/PA-PK-AS-REQ",

	ret = KRB5KDC_ERR_PREAUTH_REQUIRED;

	kdc_log(context, config, 0,
		"No preauth found, returning PREAUTH-REQUIRED -- %s",
		client_name);
	goto out;
    }
    
    /*
     * Find the client key (for preauth ENC-TS verification and reply
     * encryption).  Then the best encryption type for the KDC and
     * last the best session key that shared between the client and
     * KDC runtime enctypes.
     */

    ret = _kdc_find_etype(context, client, b->etype.val, b->etype.len,
			  &ckey, &cetype);
    if (ret) {
	kdc_log(context, config, 0, 
		"Client (%s) has no support for etypes", client_name);
	goto out;
    }
	
    ret = _kdc_get_preferred_key(context, config,
				 server, server_name,
				 &setype, &skey);
    if(ret)
	goto out;

    /* 
     * Select a session enctype from the list of the crypto systems
     * supported enctype, is supported by the client and is one of the
     * enctype of the enctype of the krbtgt.
     *
     * The later is used as a hint what enctype all KDC are supporting
     * to make sure a newer version of KDC wont generate a session
     * enctype that and older version of a KDC in the same realm can't
     * decrypt.
     *
     * But if the KDC admin is paranoid and doesn't want to have "no
     * the best" enctypes on the krbtgt, lets save the best pick from
     * the client list and hope that that will work for any other
     * KDCs.
     */
    {
	const krb5_enctype *p;
	krb5_enctype clientbest = ETYPE_NULL;
	int i, j;

	p = krb5_kerberos_enctypes(context);

	sessionetype = ETYPE_NULL;

	for (i = 0; p[i] != ETYPE_NULL && sessionetype == ETYPE_NULL; i++) {
	    if (krb5_enctype_valid(context, p[i]) != 0)
		continue;

	    for (j = 0; j < b->etype.len && sessionetype == ETYPE_NULL; j++) {
		Key *dummy;
		/* check with client */
		if (p[i] != b->etype.val[j])
		    continue; 
		/* save best of union of { client, crypto system } */
		if (clientbest == ETYPE_NULL)
		    clientbest = p[i];
		/* check with krbtgt */
		ret = hdb_enctype2key(context, &server->entry, p[i], &dummy);
		if (ret) 
		    continue;
		sessionetype = p[i];
	    }
	}
	/* if krbtgt had no shared keys with client, pick clients best */
	if (clientbest != ETYPE_NULL && sessionetype == ETYPE_NULL) {
	    sessionetype = clientbest;
	} else if (sessionetype == ETYPE_NULL) {
	    kdc_log(context, config, 0,
		    "Client (%s) from %s has no common enctypes with KDC"
		    "to use for the session key", 
		    client_name, from); 
	    goto out;
	}
    }

    log_as_req(context, config, cetype, setype, b);

    if(f.renew || f.validate || f.proxy || f.forwarded || f.enc_tkt_in_skey
       || (f.request_anonymous && !config->allow_anonymous)) {
	ret = KRB5KDC_ERR_BADOPTION;
	kdc_log(context, config, 0, "Bad KDC options -- %s", client_name);
	goto out;
    }
    
    rep.pvno = 5;
    rep.msg_type = krb_as_rep;
    copy_Realm(&client->entry.principal->realm, &rep.crealm);
    if (f.request_anonymous)
	_kdc_make_anonymous_principalname (&rep.cname);
    else
	_krb5_principal2principalname(&rep.cname, 
				      client->entry.principal);
    rep.ticket.tkt_vno = 5;
    copy_Realm(&server->entry.principal->realm, &rep.ticket.realm);
    _krb5_principal2principalname(&rep.ticket.sname, 
				  server->entry.principal);
    /* java 1.6 expects the name to be the same type, lets allow that
     * uncomplicated name-types. */
#define CNT(sp,t) (((sp)->sname->name_type) == KRB5_NT_##t)
    if (CNT(b, UNKNOWN) || CNT(b, PRINCIPAL) || CNT(b, SRV_INST) || CNT(b, SRV_HST) || CNT(b, SRV_XHST))
	rep.ticket.sname.name_type = b->sname->name_type;
#undef CNT

    et.flags.initial = 1;
    if(client->entry.flags.forwardable && server->entry.flags.forwardable)
	et.flags.forwardable = f.forwardable;
    else if (f.forwardable) {
	ret = KRB5KDC_ERR_POLICY;
	kdc_log(context, config, 0,
		"Ticket may not be forwardable -- %s", client_name);
	goto out;
    }
    if(client->entry.flags.proxiable && server->entry.flags.proxiable)
	et.flags.proxiable = f.proxiable;
    else if (f.proxiable) {
	ret = KRB5KDC_ERR_POLICY;
	kdc_log(context, config, 0, 
		"Ticket may not be proxiable -- %s", client_name);
	goto out;
    }
    if(client->entry.flags.postdate && server->entry.flags.postdate)
	et.flags.may_postdate = f.allow_postdate;
    else if (f.allow_postdate){
	ret = KRB5KDC_ERR_POLICY;
	kdc_log(context, config, 0,
		"Ticket may not be postdatable -- %s", client_name);
	goto out;
    }

    /* check for valid set of addresses */
    if(!_kdc_check_addresses(context, config, b->addresses, from_addr)) {
	ret = KRB5KRB_AP_ERR_BADADDR;
	kdc_log(context, config, 0,
		"Bad address list requested -- %s", client_name);
	goto out;
    }

    ret = krb5_generate_random_keyblock(context, sessionetype, &et.key);
    if (ret)
	goto out;
    copy_PrincipalName(&rep.cname, &et.cname);
    copy_Realm(&rep.crealm, &et.crealm);
    
    {
	time_t start;
	time_t t;
	
	start = et.authtime = kdc_time;
    
	if(f.postdated && req->req_body.from){
	    ALLOC(et.starttime);
	    start = *et.starttime = *req->req_body.from;
	    et.flags.invalid = 1;
	    et.flags.postdated = 1; /* XXX ??? */
	}
	_kdc_fix_time(&b->till);
	t = *b->till;

	/* be careful not overflowing */

	if(client->entry.max_life)
	    t = start + min(t - start, *client->entry.max_life);
	if(server->entry.max_life)
	    t = start + min(t - start, *server->entry.max_life);
#if 0
	t = min(t, start + realm->max_life);
#endif
	et.endtime = t;
	if(f.renewable_ok && et.endtime < *b->till){
	    f.renewable = 1;
	    if(b->rtime == NULL){
		ALLOC(b->rtime);
		*b->rtime = 0;
	    }
	    if(*b->rtime < *b->till)
		*b->rtime = *b->till;
	}
	if(f.renewable && b->rtime){
	    t = *b->rtime;
	    if(t == 0)
		t = MAX_TIME;
	    if(client->entry.max_renew)
		t = start + min(t - start, *client->entry.max_renew);
	    if(server->entry.max_renew)
		t = start + min(t - start, *server->entry.max_renew);
#if 0
	    t = min(t, start + realm->max_renew);
#endif
	    ALLOC(et.renew_till);
	    *et.renew_till = t;
	    et.flags.renewable = 1;
	}
    }

    if (f.request_anonymous)
	et.flags.anonymous = 1;
    
    if(b->addresses){
	ALLOC(et.caddr);
	copy_HostAddresses(b->addresses, et.caddr);
    }
    
    et.transited.tr_type = DOMAIN_X500_COMPRESS;
    krb5_data_zero(&et.transited.contents); 
     
    copy_EncryptionKey(&et.key, &ek.key);

    /* The MIT ASN.1 library (obviously) doesn't tell lengths encoded
     * as 0 and as 0x80 (meaning indefinite length) apart, and is thus
     * incapable of correctly decoding SEQUENCE OF's of zero length.
     *
     * To fix this, always send at least one no-op last_req
     *
     * If there's a pw_end or valid_end we will use that,
     * otherwise just a dummy lr.
     */
    ek.last_req.val = malloc(2 * sizeof(*ek.last_req.val));
    if (ek.last_req.val == NULL) {
	ret = ENOMEM;
	goto out;
    }
    ek.last_req.len = 0;
    if (client->entry.pw_end
	&& (config->kdc_warn_pwexpire == 0
	    || kdc_time + config->kdc_warn_pwexpire >= *client->entry.pw_end)) {
	ek.last_req.val[ek.last_req.len].lr_type  = LR_PW_EXPTIME;
	ek.last_req.val[ek.last_req.len].lr_value = *client->entry.pw_end;
	++ek.last_req.len;
    }
    if (client->entry.valid_end) {
	ek.last_req.val[ek.last_req.len].lr_type  = LR_ACCT_EXPTIME;
	ek.last_req.val[ek.last_req.len].lr_value = *client->entry.valid_end;
	++ek.last_req.len;
    }
    if (ek.last_req.len == 0) {
	ek.last_req.val[ek.last_req.len].lr_type  = LR_NONE;
	ek.last_req.val[ek.last_req.len].lr_value = 0;
	++ek.last_req.len;
    }
    ek.nonce = b->nonce;
    if (client->entry.valid_end || client->entry.pw_end) {
	ALLOC(ek.key_expiration);
	if (client->entry.valid_end) {
	    if (client->entry.pw_end)
		*ek.key_expiration = min(*client->entry.valid_end, 
					 *client->entry.pw_end);
	    else
		*ek.key_expiration = *client->entry.valid_end;
	} else
	    *ek.key_expiration = *client->entry.pw_end;
    } else
	ek.key_expiration = NULL;
    ek.flags = et.flags;
    ek.authtime = et.authtime;
    if (et.starttime) {
	ALLOC(ek.starttime);
	*ek.starttime = *et.starttime;
    }
    ek.endtime = et.endtime;
    if (et.renew_till) {
	ALLOC(ek.renew_till);
	*ek.renew_till = *et.renew_till;
    }
    copy_Realm(&rep.ticket.realm, &ek.srealm);
    copy_PrincipalName(&rep.ticket.sname, &ek.sname);
    if(et.caddr){
	ALLOC(ek.caddr);
	copy_HostAddresses(et.caddr, ek.caddr);
    }

    ALLOC(rep.padata);
    rep.padata->len = 0;
    rep.padata->val = NULL;

    reply_key = &ckey->key;
#if PKINIT
    if (pkp) {
	ret = _kdc_pk_mk_pa_reply(context, config, pkp, client, 
				  req, req_buffer, 
				  &reply_key, rep.padata);
	if (ret)
	    goto out;
	ret = _kdc_add_inital_verified_cas(context,
					   config,
					   pkp,
					   &et);
	if (ret)
	    goto out;
    }
#endif

    set_salt_padata (rep.padata, ckey->salt);

    /* Add signing of alias referral */
    if (f.canonicalize) {
	PA_ClientCanonicalized canon;
	krb5_data data;
	PA_DATA pa;
	krb5_crypto crypto;
	size_t len;

	memset(&canon, 0, sizeof(canon));

	canon.names.requested_name = *b->cname;
	canon.names.real_name = client->entry.principal->name;

	ASN1_MALLOC_ENCODE(PA_ClientCanonicalizedNames, data.data, data.length,
			   &canon.names, &len, ret);
	if (ret) 
	    goto out;
	if (data.length != len)
	    krb5_abortx(context, "internal asn.1 error");

	/* sign using "returned session key" */
	ret = krb5_crypto_init(context, &et.key, 0, &crypto);
	if (ret) {
	    free(data.data);
	    goto out;
	}

	ret = krb5_create_checksum(context, crypto, 
				   KRB5_KU_CANONICALIZED_NAMES, 0,
				   data.data, data.length,
				   &canon.canon_checksum);
	free(data.data);
	krb5_crypto_destroy(context, crypto);
	if (ret)
	    goto out;
	  
	ASN1_MALLOC_ENCODE(PA_ClientCanonicalized, data.data, data.length,
			   &canon, &len, ret);
	free_Checksum(&canon.canon_checksum);
	if (ret) 
	    goto out;
	if (data.length != len)
	    krb5_abortx(context, "internal asn.1 error");

	pa.padata_type = KRB5_PADATA_CLIENT_CANONICALIZED;
	pa.padata_value = data;
	ret = add_METHOD_DATA(rep.padata, &pa);
	free(data.data);
	if (ret)
	    goto out;
    }

    if (rep.padata->len == 0) {
	free(rep.padata);
	rep.padata = NULL;
    }

    /* Add the PAC */
    if (send_pac_p(context, req)) {
	krb5_pac p = NULL;
	krb5_data data;

	ret = _kdc_pac_generate(context, client, &p);
	if (ret) {
	    kdc_log(context, config, 0, "PAC generation failed for -- %s", 
		    client_name);
	    goto out;
	}
	if (p != NULL) {
	    ret = _krb5_pac_sign(context, p, et.authtime,
				 client->entry.principal,
				 &skey->key, /* Server key */ 
				 &skey->key, /* FIXME: should be krbtgt key */
				 &data);
	    krb5_pac_free(context, p);
	    if (ret) {
		kdc_log(context, config, 0, "PAC signing failed for -- %s", 
			client_name);
		goto out;
	    }

	    ret = _kdc_tkt_add_if_relevant_ad(context, &et,
					      KRB5_AUTHDATA_WIN2K_PAC,
					      &data);
	    krb5_data_free(&data);
	    if (ret)
		goto out;
	}
    }

    _kdc_log_timestamp(context, config, "AS-REQ", et.authtime, et.starttime, 
		       et.endtime, et.renew_till);

    /* do this as the last thing since this signs the EncTicketPart */
    ret = _kdc_add_KRB5SignedPath(context,
				  config,
				  server,
				  setype,
				  NULL,
				  NULL,
				  &et);
    if (ret)
	goto out;

    ret = _kdc_encode_reply(context, config, 
			    &rep, &et, &ek, setype, server->entry.kvno, 
			    &skey->key, client->entry.kvno, 
			    reply_key, &e_text, reply);
    free_EncTicketPart(&et);
    free_EncKDCRepPart(&ek);
    if (ret)
	goto out;

    /* */
    if (datagram_reply && reply->length > config->max_datagram_reply_length) {
	krb5_data_free(reply);
	ret = KRB5KRB_ERR_RESPONSE_TOO_BIG;
	e_text = "Reply packet too large";
    }

out:
    free_AS_REP(&rep);
    if(ret){
	krb5_mk_error(context,
		      ret,
		      e_text,
		      (e_data.data ? &e_data : NULL),
		      client_princ,
		      server_princ,
		      NULL,
		      NULL,
		      reply);
	ret = 0;
    }
#ifdef PKINIT
    if (pkp)
	_kdc_pk_free_client_param(context, pkp);
#endif
    if (e_data.data)
        free(e_data.data);
    if (client_princ)
	krb5_free_principal(context, client_princ);
    free(client_name);
    if (server_princ)
	krb5_free_principal(context, server_princ);
    free(server_name);
    if(client)
	_kdc_free_ent(context, client);
    if(server)
	_kdc_free_ent(context, server);
    return ret;
}
Example #4
0
static krb5_error_code
init_as_req (krb5_context context,
	     KDCOptions opts,
	     krb5_creds *creds,
	     const krb5_addresses *addrs,
	     const krb5_enctype *etypes,
	     const krb5_preauthtype *ptypes,
	     const krb5_preauthdata *preauth,
	     krb5_key_proc key_proc,
	     krb5_const_pointer keyseed,
	     unsigned nonce,
	     AS_REQ *a)
{
    krb5_error_code ret;
    krb5_salt salt;

    memset(a, 0, sizeof(*a));

    a->pvno = 5;
    a->msg_type = krb_as_req;
    a->req_body.kdc_options = opts;
    a->req_body.cname = malloc(sizeof(*a->req_body.cname));
    if (a->req_body.cname == NULL) {
	ret = ENOMEM;
	krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	goto fail;
    }
    a->req_body.sname = malloc(sizeof(*a->req_body.sname));
    if (a->req_body.sname == NULL) {
	ret = ENOMEM;
	krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	goto fail;
    }
    ret = _krb5_principal2principalname (a->req_body.cname, creds->client);
    if (ret)
	goto fail;
    ret = _krb5_principal2principalname (a->req_body.sname, creds->server);
    if (ret)
	goto fail;
    ret = copy_Realm(&creds->client->realm, &a->req_body.realm);
    if (ret)
	goto fail;

    if(creds->times.starttime) {
	a->req_body.from = malloc(sizeof(*a->req_body.from));
	if (a->req_body.from == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	    goto fail;
	}
	*a->req_body.from = creds->times.starttime;
    }
    if(creds->times.endtime){
	ALLOC(a->req_body.till, 1);
	*a->req_body.till = creds->times.endtime;
    }
    if(creds->times.renew_till){
	a->req_body.rtime = malloc(sizeof(*a->req_body.rtime));
	if (a->req_body.rtime == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	    goto fail;
	}
	*a->req_body.rtime = creds->times.renew_till;
    }
    a->req_body.nonce = nonce;
    ret = _krb5_init_etype(context,
			   KRB5_PDU_AS_REQUEST,
			   &a->req_body.etype.len,
			   &a->req_body.etype.val,
			   etypes);
    if (ret)
	goto fail;

    /*
     * This means no addresses
     */

    if (addrs && addrs->len == 0) {
	a->req_body.addresses = NULL;
    } else {
	a->req_body.addresses = malloc(sizeof(*a->req_body.addresses));
	if (a->req_body.addresses == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	    goto fail;
	}

	if (addrs)
	    ret = krb5_copy_addresses(context, addrs, a->req_body.addresses);
	else {
	    ret = krb5_get_all_client_addrs (context, a->req_body.addresses);
	    if(ret == 0 && a->req_body.addresses->len == 0) {
		free(a->req_body.addresses);
		a->req_body.addresses = NULL;
	    }
	}
	if (ret)
	    return ret;
    }

    a->req_body.enc_authorization_data = NULL;
    a->req_body.additional_tickets = NULL;

    if(preauth != NULL) {
	size_t i;
	ALLOC(a->padata, 1);
	if(a->padata == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	    goto fail;
	}
	a->padata->val = NULL;
	a->padata->len = 0;
	for(i = 0; i < preauth->len; i++) {
	    if(preauth->val[i].type == KRB5_PADATA_ENC_TIMESTAMP){
		size_t j;

		for(j = 0; j < preauth->val[i].info.len; j++) {
		    krb5_salt *sp = &salt;
		    if(preauth->val[i].info.val[j].salttype)
			salt.salttype = *preauth->val[i].info.val[j].salttype;
		    else
			salt.salttype = KRB5_PW_SALT;
		    if(preauth->val[i].info.val[j].salt)
			salt.saltvalue = *preauth->val[i].info.val[j].salt;
		    else
			if(salt.salttype == KRB5_PW_SALT)
			    sp = NULL;
			else
			    krb5_data_zero(&salt.saltvalue);
		    ret = add_padata(context, a->padata, creds->client,
				     key_proc, keyseed,
				     &preauth->val[i].info.val[j].etype, 1,
				     sp);
		    if (ret == 0)
			break;
		}
	    }
	}
    } else
    /* not sure this is the way to use `ptypes' */
    if (ptypes == NULL || *ptypes == KRB5_PADATA_NONE)
	a->padata = NULL;
    else if (*ptypes ==  KRB5_PADATA_ENC_TIMESTAMP) {
	ALLOC(a->padata, 1);
	if (a->padata == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	    goto fail;
	}
	a->padata->len = 0;
	a->padata->val = NULL;

	/* make a v5 salted pa-data */
	add_padata(context, a->padata, creds->client,
		   key_proc, keyseed, a->req_body.etype.val,
		   a->req_body.etype.len, NULL);

	/* make a v4 salted pa-data */
	salt.salttype = KRB5_PW_SALT;
	krb5_data_zero(&salt.saltvalue);
	add_padata(context, a->padata, creds->client,
		   key_proc, keyseed, a->req_body.etype.val,
		   a->req_body.etype.len, &salt);
    } else {
	ret = KRB5_PREAUTH_BAD_TYPE;
	krb5_set_error_message (context, ret,
				N_("pre-auth type %d not supported", ""),
			       *ptypes);
	goto fail;
    }
    return 0;
fail:
    free_AS_REQ(a);
    return ret;
}
Example #5
0
static krb5_error_code
init_as_req (krb5_context context,
	     KDCOptions opts,
	     const krb5_creds *creds,
	     const krb5_addresses *addrs,
	     const krb5_enctype *etypes,
	     AS_REQ *a)
{
    krb5_error_code ret;

    memset(a, 0, sizeof(*a));

    a->pvno = 5;
    a->msg_type = krb_as_req;
    a->req_body.kdc_options = opts;
    a->req_body.cname = malloc(sizeof(*a->req_body.cname));
    if (a->req_body.cname == NULL) {
	ret = ENOMEM;
	krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	goto fail;
    }
    a->req_body.sname = malloc(sizeof(*a->req_body.sname));
    if (a->req_body.sname == NULL) {
	ret = ENOMEM;
	krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	goto fail;
    }

    ret = _krb5_principal2principalname (a->req_body.cname, creds->client);
    if (ret)
	goto fail;
    ret = copy_Realm(&creds->client->realm, &a->req_body.realm);
    if (ret)
	goto fail;

    ret = _krb5_principal2principalname (a->req_body.sname, creds->server);
    if (ret)
	goto fail;

    if(creds->times.starttime) {
	a->req_body.from = malloc(sizeof(*a->req_body.from));
	if (a->req_body.from == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	    goto fail;
	}
	*a->req_body.from = creds->times.starttime;
    }
    if(creds->times.endtime){
	ALLOC(a->req_body.till, 1);
	*a->req_body.till = creds->times.endtime;
    }
    if(creds->times.renew_till){
	a->req_body.rtime = malloc(sizeof(*a->req_body.rtime));
	if (a->req_body.rtime == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	    goto fail;
	}
	*a->req_body.rtime = creds->times.renew_till;
    }
    a->req_body.nonce = 0;
    ret = krb5_init_etype (context,
			   &a->req_body.etype.len,
			   &a->req_body.etype.val,
			   etypes);
    if (ret)
	goto fail;

    /*
     * This means no addresses
     */

    if (addrs && addrs->len == 0) {
	a->req_body.addresses = NULL;
    } else {
	a->req_body.addresses = malloc(sizeof(*a->req_body.addresses));
	if (a->req_body.addresses == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_message(context, ret, N_("malloc: out of memory", ""));
	    goto fail;
	}

	if (addrs)
	    ret = krb5_copy_addresses(context, addrs, a->req_body.addresses);
	else {
	    ret = krb5_get_all_client_addrs (context, a->req_body.addresses);
	    if(ret == 0 && a->req_body.addresses->len == 0) {
		free(a->req_body.addresses);
		a->req_body.addresses = NULL;
	    }
	}
	if (ret)
	    goto fail;
    }

    a->req_body.enc_authorization_data = NULL;
    a->req_body.additional_tickets = NULL;

    a->padata = NULL;

    return 0;
 fail:
    free_AS_REQ(a);
    memset(a, 0, sizeof(*a));
    return ret;
}